The present invention relates to a radio receiver, and more particularly to a preset station selecting device for use in a radio receiver.
Recently, radio receivers have come into wide use which can be electronically tuned to broadcasting frequencies using a phase-locked loop. Especially, in radio receivers used in automotive vehicles, in addition to the electronic tuning function, a station selecting device has come into practical use which uses tuning frequency information stored in a memory for tuning into broadcasting stations. This device has a function to write the frequency information relating to a selected station into a memory, and to read the information out of the memory, in order to select the broadcast station. Commands for these operations are sent by switching operations. This station selecting device is so constituted that writing in the memory is effected by receiving a write-ready command and a write command. Thus two switches are needed, one for making the memory ready for writing, and another for actually writing frequency information into the memory. In presetting the radio receiver, these two switches are both operated.
When an automotive vehicle is making a long trip, the broadcasting stations which can be received are liable to vary from place to place. In this case, a new station cannot be received, using the old tuning frequency used so far, although the energy of the new broadcasting frequency may be sufficiently strong. When the new station is desired to be received in automatic selection mode, its frequency must be newly set.
In such a case, two switches must be operated, one for starting preparation for writing, and the other for starting actual writing, in the prior art devices.